1/17/17 Smith Intro to antimicrobials TEST #1 Flashcards
How many lbs of your total body weight are microbes either in or on your body?
1-3 lbs
For every human gene in your body, how many microbial genes are there?
360
Define antibiotic?
-Low molecular substance produced by a microorganism that inhibits or kills other microorganisms
T/F
All antibiotics are antimicrobials, no all antimicrobials are antibiotics.
True
Define antimicrobial.
-Any substance of natural (penicillin and alkaloids) , semisynthetic, or synthetic origin that kills or inhibits the growth of microorganisms
What is bacteriocidal?
Kills the organisms
What is bacteriostatic?
-Stops the organisms from growing
T/F
A drugs spectrum of action is the same as its useful therapeutic range
False
It is not the same
Why is something classified as a broad spectrum drug?
-Active against wide range of microorganisms
Why is something classified as a narrow spectrum drug?
-They are only useful against particular species of microorganisms
T/F
There are antimicrobials that are effective against all microbes
False
There are no antimicrobials effective against all microbes
T/F
When a patient has a sore throat, fever, or aches and pains it is sufficient alone to prescribe antimicrobials.
False
It is sufficient alone to prescribe
When you prescribe an antimicrobial do you want to have a broader spectrum or narrower spectrum?
-Narrow spectrum so you don’t kill the good bacteria
What is the minimal inhibitory concentration?
-The lowest concentration of an antibiotic that will inhibit the growth of a bacterial strain
The more susceptible a drug is on a bacteria what do you look for on a disc diffusion test?
-A larger zone of inhibition
What does a broth dilution test determine?
-The MIC and the MBC (minimum bactericidal concentration)
What type of antibiotics usually have similar MIC and MBC values?
-Bactericidal
What type of antibiotics have much higher MBC than MIC values?
-Bacteristatic
If you have a treatment with an identified pathogen what is it called?
-A definitive treatment
What is pharmacokinetics?
- The relationship of the time course of drug ADME
- What the body does to the drug
What is pharmacodynamics
- What the drug does to the body
- Efficacy and Toxicity
What are the two goals of choosing a dose regimen?
- Achieve a bactericidal concentration at the site
- Discourage emergence of resistant bacteria
At the site of infection what can bind to drugs and thus inactivate some antimicrobial therapies?
- Pus
- Hemoglobin
What phase of bacterial growth is most sensitive to antimicrobial intervention?
-Log phase
What is a type I drug?
-Concentration -dependence
What is a type II drug?
-Time-dependence (dose doesn’t matter but you want it in the system longer)
What is a type III drug?
-Time-dependent with persistent effects
What is the most important factor in a type I drug?
-C max (maximum concentration)
T/F
when selectivity is high, the risk of adverse effects are reduced (example cell wall targets in humans)
True
If you have an adverse effect on human cells resulting from the same mechanism as the antimicrobial effect what type of adverse effect do you have?
-Analogous
T/F
You can have adverse effects independent of antimicrobial action
True
What are the two usual routes of clearance of drugs in the body?
- Liver
- Kidney
What are four mechanisms of action for antimicrobial therapies?
- Cell wall and cell membrane
- Protein synthesis
- Inhibition of metabolic pathways
- Nucleic acid synthesis
What improves efficacy of a drug?
-Synergism
What is a superinfection?
-Overgrowth of pathogens resulting from use of antimicrobial drugs
T/F
The larger the disruption of the microbiome, the greater the opportunity for pathogens to overgrow
True
What are two causes of superinfections?
- Use of a broad-spectrum antimicrobial agent
- Use of a higher than normal concentration of antimicrobial drug
